Lee'U was an Alshain male, who was emperor of his people. (DIS: "Kobayashi Maru")

In 3190, Alshain IV was visited by the USS Discovery. Emperor Lee'U and his entourage met with Captain Michael Burnham and Cleveland Booker, who offered to freely gift dilithium to the Alshain on behalf of the United Federation of Planets, in the hopes of re-establishing diplomatic relations. Lee'U expressed skepticism to the Federation's intentions, in spite of Burnham's claims that the gift would come with "no string attached", suspecting they were only giving dilithium for a future favor. Subsequently, one of his aides informed him of a third lifeform detected on Booker's ship. Burnham and Booker tried to explain it was the latter's pet, Grudge, but the series of misunderstandings provoked Lee'U and his entourage to attack the pair, believing Grudge to be a captive monarch. Despite pursuing them all the way to Booker's ship, Lee'U was puzzled that Discovery fixed his planet's satellite system and provided their dilithium in spite of his actions. He hailed Discovery to question Burnham's actions and she replied that being charitable was the Federation's very nature. (DIS: "Kobayashi Maru")

Emperor Lee'U later represented his people at the conference of Federation member worlds and allies to decide on the actions regarding the Dark Matter Anomaly. He opposed General Diatta Ndoye's calls for attacking Species 10-C, stating that the Federation had taught him that they need not fear the unknown and that it would be wrong to presume ill intent on part of the 10-C. (DIS: "...But to Connect")